Container having a series of convolutions along the side walls thereof and container blank for forming same



J ly 2, 1968 H. s. MALBY ETAL 3,390,327

' CONTAINER HAVING A SERIES OF CONVOLUTIONS ALONG THE SIDE WALLS THEREOFAND CONTAINER BLANK FOR FORMING SAME Filed April 5, 1966 INVENTORS-HOWARD 8. MALE) FRED M. REC/(NAGEL United States Patent 3,390,827CONTAINER HAVING A SERIES OF CONVOLU- TIONS ALONG THE SIDE WALLS THEREOFAND CONTAENER BLANK FOR FORMING SAME Howard S. Malby, Westfield, andFred M. Recknagel,

Clark, N.J., and Roger S. Tobie, Brooklyn, N.Y., assigners to ChevronResearch Company, San Francisco, Califi, a corporation of Delaware FiledApr. 5, 1966, Ser. No. 549,087 (Filed under Rule 47(a) and 35 U.S.C.116) 7 Claims. (Cl. 229-8) ABSTRACT OF THE DICLOSURE A container andcontainer blank of plastic material adapted to have a plurality of sidepanels, the said panels having at least four sinuous foldlines and tostraight foldlines; the straight foldlines adapted to allow said blankto be folded fiat to form a low silhouette; the sinuous foldlinesselectively foldable as the blank is erected to form a series ofconvolutions along the side walls of the container.

This invention relates to the manufacture of closed containersconstructed of plastics materials. It relates more particularly toclosed containers foldable from fiat container blanks to uprightconfigurations of square or rectangular cross sections for the packagingof liquid materials, such as milk.

. Briefly, the primary object of the present invention is to provideside walls of such containers on which a vertical lifting force can beexerted, as during the dispensing of the container contents, withoutinwardly deforming the side walls toward the center of the container andwithout complicating the usual score line pattern of the containerblanks from which the containers are formed.

In accordance with the present invention, a series of convolutions areformed along the side walls of such containers to provide the diagonallysloping surface area on which a vertical lifting force can be exertedwithout deforming the side walls of the container, Preferably, theconvolutions are periodically disposed along the walls, say every one totwo inches, and are provided by an appropriately formed score pattern offoldlines which facilitates the selective folding of the side panels ofthe container blank from a flat to an undulating orientation.

It is well known in the packaging art to construct container blanks byscoring foldable sheets of cardboard, plastics and the like with aseries of foldlines to divide the blank into a series of panel areas.For example, the foldline may be arranged to form a top panel area atthe top of the container, a central panel area over the main longsection of the blank, and a bottom panel area at the bottom. Usually thefoldlines are oriented in straightline relationships for a variety ofreasons. For example, the designer may find straight-line relationshipseasier to visualize in the initial stages of development of thecontainer blank. It is therefore easier for him to design, in arelatively short time, the container and blank. However, thestraight-line foldline patterns of the prior art container blanksproduce containers having fiat side walls normal to flat bottom walls.

After the container is filled with fluids or solids, these contents areusually dispensed by a person lifting the container by gripping opposedside walls with his hand. The hand pressure must be sufficient toadequately grip the container but must be below the rupture modulus ofthe plastics material. Accordingly, if the gripping area of the hand iswet or the hand pressure is too great, there is an increased likelihoodof the contents spilling from the container. Either the container mayslip from the 3,39%,82? Patented July 2, 1968 hand as it is lifted orthe side panels may become overstressed with minute tears resultingalong segments of the sides or bottom panels of the container.

The present invention, however, provides for the arrangement of thefoldlines across a container blank in which the central panel area isprovided with a combination of straight and sinuous foldlines that allowselective reorientations of the blank to a finalized container havingbetter gripping characteristics as well as an esthetically enhancedappearance. Briefly, this foldline pattern includes first and secondhorizontal foldlines which mark the top and bottom boundaries of thecentral panel area. At vertically spaced intervals, the pattern alsoincludes at least four vertical foldlines marking the corners of thecompleted container which are formed in sinuous patterns relative toeach other. Although preferably the amplitudes of these foldlines areconstant and equal, the phase of adjacent foldlinesas viewed on the sameside of a flat blankpreferably differs by degrees. Thus as the centralpanels are inwardly folded along such pair of adjacent foldlines, theseries of convolutions formed along any one side wall terminate in edgeengagement with oppositely contoured convolutions of the two adjacentside walls. However, on opposed side walls, horizontally alignedconvolutions are similarly contoured. Consequently, the convex contourof the convolutions of such side walls provides horizontally alignedgripping surfaces on which the vertical lifting forces, as provided by apersons hand, can be exerted without cleforming the side wall of thecontainer.

Other objects and features of the present invention will become moreapparent after an examination of the following description of anembodiment of the invention taken in conjunction with the drawings, inwhich:

FIGURE 1 is an elevational view with partial sections, of a fiat blankwhich is fashioned into a container of the present invention;

FIGURE 2 is an elevational view, with partial sections. of the containerof the present invention;

FIGURE 3 is a side view, with partial sections, of the container of thepresent invention;

FIGURE 4 is a sectional view taken along line 44 of FIGURE 2;

FIGURE 5 is a sectional View taken along line 5-5 of FIGURE 2; and

FIGURE 6 is a bottom view of the container of the present invention.

Referring now to the drawings, particularly FIGURE 1, container blank 10is fashioned with a series of foldlines dividing the blank into aplurality of panel areas. When folded, usually toward the geometriccenter 10a of the blank. These panel areas form a completed container ofsquare or rectangular cross section.

As indicated in FIGURE 1, the blank 10 includes a central panel area 11which is fashioned to the side walls or body portion of the container,upper panel area 12 which forms the top closure of the container andlower panel area 13 which forms the bottom of the container. The nearsides of the panel areas 11, 12 and 13 are illustrated in FIGURE 1; therear side is identical in pattern to the foldlines as illustrated. Thenear and remote sides integrally connect to each other along verticalfoldlines 14 and 15 which allow the blank to lie flat in a common plane,as defined by lower primary foldline 16 at the lower edge of the blank.

Bottom panel area 13 is defined between upper horizontal foldline 17 andprimary foldline 16 and includes pairs of bottom panels 18a, 18b, 19a,19b, 20a and 2017, each of said pairs being integrally connected alongprimary foldline 16. At the vertical side edges, each bottom panel isseen to be in integral edge engagement with adjacent panels along thelower vertical extensions of vertical foldlines 4t), 41, 42 and 43 oralong the bottom portions of previously mentioned foldlines 14 and 15 toprovide a seamless bottom construction as described in more detail in acopending application assigned to the assignee of the presentapplication (High-Strength Container and Container Blank Having SeamlessBottom Walls, and Method of Forming Same, Ser. No. 549,086 filed Apr. 5,1966, Howard S. Malby, Fred M. Recknagel and Roger S. Tobie).

Briefly, at each end of the panel pairs 18a, 18b, 20a and 20b, diagonalfoldlines 21a, 21b, 22a and 22b divide the panel pairs into a pluralityof right triangular elements. The container blank is thus adapted to befolded at the diagonal foldlines 21a, 21b, 22a and 22b as pressure isapplied along foldlines 14 and 15, to form these elements into a pair oftwin-thickness tuck-up panels 39 and 31, as shown in FIGURE 6. Asillustrated, the tuck-up panels are triangularly shaped and convenientlyattached at vertices 32 to the exterior surfaces of the bottom panels19a and 1%. At the attaching surfaces, the bottom panels 19a and 1% arenot formed in a common plane normal to the side walls of the container,but are reentrantly shaped with respect thereto. For this purpose, theprimary foldline 16 of the blank is formed such that it slopesdiagonally across the blank. Accordingly, its length dimension isgreater than that of edges 25 and 26 of these panels. Relative movementof the panels by pivoting about primary foldline 16 reorients them withrespect to the center of the container.

Upper panel area 12 is at the top of the blank formed of a plurality ofpairs of panel extensions 33, 34 and 35 inwardly foldable to provide aclosure area and a dispensing spout for the container. These extensionsgive the completed container a characteristic closure as, for example, agable shape having an outwardly flexible spout well known in the art.

Central area 11 is fashioned to form the side walls of the completedcontainer nad comprises a series of contiguous side panels a, 45b, 46a,46b, 47a and 47b defined by four vertical foldlines 40, 41, 42 and 43and the previously mentioned exterior foldlines 14 and 15-. The sidepanels 45a and 4512, as well as panels 47a and 47b, are longitudinallydivided by the vertical foldlines 14 and 15 which allow, as previouslyindicated, the blank to be folded flat to a low silhouette. However,side panels 46a and 46b are unmarked in this regard. Each of these sidepanels 45a, 45b, 46a, 46b, 47a and 4717, however, is contiguouslyattached to adjacent panels to form a fluid-tight enclosure alongrespective foldlines 4t), 41, 42 and 43. In the horizontal direction,these panels are defined between foldline 44 at the upper boundary andby foldline 17 at the lower boundary.

Foldlines 4-0, 41, 42 and 43 serpentine periodically about imaginarystraight lines extending vertically along the central area 11. The endsof the foldlines terminate in contact with horizontal foldlines 44 and17.

The amplitude of the foldlines 40, 41, 42 and 43 relative to theseimaginary lines are maximum where the slopes of the foldlines are zero(i.e., at the peaks and valleys) and minimum where the foldlines crossthe imaginary lines. Although the magnitude of the foldline amplitudeperiodicaly changes as a function of the length of the foldlines, theabsolute range of such variation is a constant.

In any horizontal plane normal to the axis of symmetry of the blank,however, the variation in the amplitudes of the two horizontally alignedfoldlines (i.e., foldlines in the same plane as the broad surfaces ofthe blank) are not the same but instead are inversely related. Thus thephase of the foldlines 4t and 41 is the inverse conjugate of that of thefoldlines 42 and 43; or, in other words, there is a phase difference of180 degrees between these foldlines. Accordingly, the half cycles of thefoldlines 49 and 41 at the intersection with the horizontal foldlines 44or 17 form convexly contoured wavelets 48 relative to the geometriccenter 10a of the blank. Horizontally aligned across the blank, theopposing foldlines 42 and 43 are inversely arranged relativeto'-foldlines 40 and are such that concavely contoured wavelets 49 areformed at the intersection with horizontal foldlines 44 and 17. Thereason for the inverse relationship of the foldlines is explained below.

Pivoting side panels 45a, 45b, 47a and 4712 about foldlines 14 and 15form these panels into side walls normal to the side panels 46a and4621. For this purpose, pressure is inwardly applied toward thegeometric center 1041 of the blank along the en ire length of thefoldlines 14 and 15. Panels 46a and 46b also pivot relative to thepanels 45a, 45b, 47a and 471) at the vertical corner foldline's'40, 41,42 and 43 as such pressure is applied. After the pressure is released,the central areas of the panels are no longer flat, but are fashioned,as viewed in FIGURES 2 and 3, into a series of convolutions. Asindicated, the contour of the convolutions of adjacent side wallsdiffers. Accordingly, the numeral 50 is used to designate similarlyoriented convolutions on opposed panels 45a, 45b, 47a and 4712 (FIGURE4) while the'nu-meral 51'is used to indicate convolutions on opposedpanels 464 and'46b (FIGURE 5).

As indicated in FIGURES 2 and 3, the contour of convolutions varies inaccordance with the pattern of the foldlines from which the convolutionsare formed. Accordingly, in similar horizontal planes, opposingconvolutions of the side walls have similar contours, rwhile adjacentlylocated convolutions have inversely oriented contours. For example,between the horizontal planes along lines 4-4 and 55 of FIGURE 2,convolutions 50 are seen to be inwardly directed toward the geometriccenter 10ai.e., convexly oriented relative to center 10a-while, for thesame horizontal planes projected into FIGURE 3, the convolutions 51 ofpanels 46a and 46b are outwardly directed relative to the center10a-i.e., concave relative to the center 10a. In a similar manner, thehorizontal distances extending between the interior surface of theopposed convolutions may vary from a maximum in the 'apexes of theconcave convolutions to a minimum at the troughs of the convexedconvolutions (FIGURES 4 and 5). In that manner, the container may belifted to dispense thecontents by inserting the fingers and thumb of thehand on the convex surface of the convolutions on opposed side panels toprovide a vertical lifting force to the container without inwardlydeforming its side walls.

These and other advantages are obtainable when operating in accordancewith the foregoing embodiment of the invention or with any of numerousvariations that could be made by those skilled in the art withoutdeparting from the spirit of the invention; and all such variations thatfall within the scope of the appended claims are intended to be embracedthereby.

We claim:

1. A materialsenclosure container of plastics material or the likefashioned from a fiat container blank having a series of foldlinesdividing said blank into at least a side panel area of a plurality ofside panels integrally joined together along vertically extending edgesto form a fluidtight side closure area, com rising a body member havingfour coextensive continuous side walls, two opposed side Walls withrespect to the geometric center of said container being provided withcoplanar straight vertically extending foldlines adapted to allowfolding therealong so as to provide a fiat container blank prior toerection to form said container, each of said side walls integrallyengaging two adjacent side walls along vertical edges thereof, andhaving a series of convolutions therealong extending directionallyacross the full transverse dimension of said side wall, saidconvolutions including periodically spacedapart sections convexly andconcavely contoured with respect to said geometric center of saidcontainer to cooperatively provide a series of horizontally alignedgripping areas in which lifting forces can be exerted to dispensematerial from said container and to add strength along said two opposedside walls provided with said coplanar straight vertical foldlines, atop closure engaging the upper edge of said body member, and bottommeans in operative engagement with the lower edge of said body member toform a fluid-tight container.

2. Said container of claim 1 in which each convolution of said series ofconvolutions joins in edge engagement with an oppositely contouredconvolution of said adjacent side wall.

3. Said container of claim 1 in which said bottom means comprises aseamless bottom wall integrally and continuously engaging a lower edgeof said body member along a horizontal continuous foldline.

4. A container blank to form a materials-enclosing container ofrectangular or square cross section formed of plastics material or thelike in which a series of foldlines divides said blank into foldablepanel areas, comprising a plurality of top closure panels, a pluralityof side panels attached to said top closure panels along a firsthorizontal foldline, and a plurality of bottom panels attached to saidside panels as extensions thereof along a second horizontal foldline,said plurality of side panels having four vertically directed sinuousfoldlines adapted to form corners of said container and two verticallydirected straight coplanar fol'dlines adapted to allow said blank to befolded flat therealong to form a low silhouette, said sinuous foldlinesand said straight foldlines adapted to allow said side panels definedthereby to form a continuous fluid-tight side closure area, each of saidsinuous foldlines being so constructed and attached to allow said sidepanels defined thereby to be selectively folded to form a series ofconvolutions therealong when said side panels are folded to form saidcontainer.

5. Said container blank of claim 4 in which a pair of said verticallydirected sinuous foldlines is an inverse conjugate of the remaining pairof said foldlines.

6. Said container blank of claim 4 in which each of said bottom panelshas at least one terminating edge in an integral engagement with aterminating edge of another of said bottom panels to form a fluid-tightbottom closure area.

7. Said container blank of claim 6 in which said fluidtight bottomclosure area includes a remote primary edge in coplanar alignment withat least said two opposed straight vertical foldlines of said sidepanels to thereby place opposed broad surfaces of said side, top andbottom panels in a juxtapositional relationship and form said flatcontainer blank of low silhouette.

References Cited UNITED STATES PATENTS 3,021,045 2/ 1962 Morris 229-8 XFOREIGN PATENTS 519,577 4/ 1940 Great Britain.

942,748 11/1963 Great Britain.

DONALD F. NORTON, Primary Examiner.

